Given a brief description of features and specifications of reinforcement of the class Aн600C (brand 20G2SFBA). Areas of rational application of reinforcing steel of the class AH600C (brand 20G2SFBA) are considered at compression with casual eccentricity, non-central compression with small and big eccentricity in compressed structures of squared cross-section. Are given analytical dependences in the calculation of structures in the first and second group of limit states.

The analysis of the regulatory documents of the Russian Federation in terms of the requirements for accounting for the responsibility of buildings and structures when calculating for seismic impacts is given. For discussion, an approach is proposed to the differentiated assignment of the responsibility coefficient Kо for individual structural elements (columns) of a multi-storey monolithic reinforced concrete frame building when determining calculated seismic loads. Based on the results of calculations for an emergency settlement situation associated with the expected initial local destruction of the column, taking into account its different location in the plan and height for the columns, the values of the coefficients of significance of the location in the plan and the location in height are determined, taking into account the analysis of the calculated volumes of destruction, and are further used to clarify the values of the coefficients of responsibility Kо.